The present invention relates to a hypoxia detection and alleviation system, and more particularly to a hypoxia detection and alleviation system to be used by a pilot of an aircraft, and even more particularly to a hypoxia detection and alleviation system utilizing pupillometry to monitor one or both pupils of the pilot, and most particularly to a hypoxia detection and alleviation system coupled to an onboard oxygen system (wherein the oxygen system is configured to provide a higher dosage of oxygen to the pilot upon detection of hypoxic stress. While described herein as a system for detecting and alleviating hypoxia, it should be understood by those skilled in the art that the present system can be used to detect and alleviate additional causes of reduced cognitive function that may be experienced by a pilot. Additionally, the onboard oxygen system may be a stored supply of supplemental oxygen, such as a storage tank filled with oxygen gas or liquid oxygen, or may include an onboard oxygen generating system commonly referred to as OBOGS.
Hypoxia reports regarding aircraft pilots continue to gain significant attention, including those involved with military fighter aircraft such as the F-22 and F-35 as well as private and commercial non-military aircraft. Pilots are routinely exposed to altitudes that are significantly higher than sea level. These high altitudes reduce the partial pressure of oxygen in their lungs. In extreme cases the reduced partial pressure of oxygen deprives the crew and passengers of adequate oxygen supply leading to hypoxia. Early symptoms of hypoxia may include light-headedness, fatigue and nausea. Prolonged exposure to reduced oxygen or a more rapid onset of hypoxia (such as may be encountered during aviation) can lead to confusion, disorientation, severe headaches, and may even lead to death. Studies by the US military have demonstrated that for normal, healthy individuals, significant physiological responses occur at altitudes greater than about 10,000 feet above sea level (ASL) while other studies have shown that a reduction in night vision and mild hypoxia can occur at altitudes as low as 5,000 feet ASL. Additionally, as a person ages, his or her susceptibility to hypoxia varies widely.
To account for the reduced oxygen and possibility of a hypoxic event at high altitudes, aircraft are generally pressurized (commercial airliners) or include supplemental oxygen, such as supplemental oxygen tanks or an onboard oxygen gas generation system (OBOGS), either of which may supply the pilot with oxygen enriched gas through a gasmask worn by the pilot when at high altitudes. Nevertheless, risks of hypoxia still remain. Research has shown that there exists a clear link between pupil size and the early effects of hypoxia. Indeed, it has been found that the eyes may be the first indicators of the onset of hypoxia, either through loss of peripheral vision, change in color perception or other optical anomalies. Basic functions of the eye can be measured through the size and response of the pupil and this response can be measured non-invasively using a technique known as pupillometry. The measurement of the pupil size and/or response provides a valid means to detect the early effects of hypoxia.
Thus, what is needed is a hypoxia detection and alleviation device that may monitor pilots and detect early indications of hypoxia so that the pilot (or the oxygen system/OBOGS through automatic control by the aircraft's control system) may take corrective actions to alleviate the conditions leading to hypoxia, such as lowering altitude or increasing the partial pressure of oxygen being supplied to the pilot.